Fluid streams containing combinations of gases and liquids, and with or without solids, are conditioned in a variety of ways. Undesirable elements contained in a fluid stream may be removed by mechanical means or by chemical means. Often particulate is used in the conditioner to enhance the operation of the chemical or mechanical process.
Prior art devices of this kind have generally been concerned to develop a reasonably compact efficient conditioner which allows for sufficient contact between the fluid stream and the conditioning apparatus to properly condition the fluid stream. Where conditioning is conducted with the use of particulate, it is also important in many applications to provide means to regenerate the particulate and means to prevent clumping of the particulate. Means are often provided to prevent channeling of the fluid stream.
One way to provide for this contact is to provide the conditioning means in a columnar or tower form and to force the fluid stream through. Generally in an apparatus of this type, a relatively large amount of energy will be required to move the fluid stream because of the depth of the particulate. Such designs also make it difficult to provide for the removal and regeneration of the particulate.
Another more common way is to provide for a long path during which there is contact between the fluid stream and the conditioning means. Such a long path requires a very large conditioning apparatus unless means are taken to save space. One method is to make the path helical.
Thus in U.S. Pat. No. 2,688,807, Ginther, issued Sept. 14, 1954, a drying apparatus is disclosed in which a gas stream passes along the length of a trough mainly contacting the uppermost particles of the particulate contained in the trough. However, in the Ginther apparatus, a relatively smaller passage is provided for the gas than in the columnar or tower configuration. This allows for a relatively smaller volumetric flow of gas through the apparatus. In order to deal with an efficient quantity of gas, a relatively higher gas velocity must be utilized, thus decreasing the contact time between the gas and the particulate.